Vascular masses tend to develop rapidly over minutes to hours and may be pulsatile.

Idiopathic/ iatrogenic causes

a. Postoperative complications

b. Idiopathic etiologies would be a dx of exclusion

Toxic and metabolic causes

a. Several thyroid conditions such as hyperthyroidism and hypothyroidism can cause toxic or metabolic derangement that may present as neck masses, including hot and cold nodules, goiters and inflammatory thyroiditis